Hypotension during hemodialysis is a common occurrence, and results in significant patient discomfort and inefficient use of dialysis time and monitoring personnel. The causes of dialysis-related hypotension are several in origin, and in general result from an inability to increase peripheral resistance and cardiac output during hemodialysis. It has been the practice in the art to monitor the blood pressure of a dialysis patient, either manually or automatically, at periodic intervals and to initiate therapeutic intervention by monitoring personnel in the event of a hypotensive episode. If an episode occurs between monitoring intervals or is not detected by manual or automated blood pressure monitoring, the dialysis monitoring personnel are usually not aware of a potential problem until the patient has a massive reaction and exhibits substantial distress. In any event, the several maneuvers heretofore employed to manage and correct a hypotensive episode, including injection of sodium solution into the patient's bloodstream and/or reducing fluid extraction rate, require manual intervention by dialysis personnel and continued actual observation and monitoring of the patient until the episode is corrected. A high ratio of dialysis personnel to patients is therefore required.
It is therefore an object of the present invention to provide a fully automated method and apparatus for continuously monitoring patient vital signs during hemodialysis and automatically initiating therapeutic intervention upon occurrence of a hypotensive episode without requiring manual intervention by dialysis personnel.
Another and more specific object of the invention is to provide a method and system for detecting potential on-set of a hypotensive episode before the episode becomes acute by continuously monitoring patient vital signs, namely blood pressure and heart rate, and for automatically initiating therapeutic intervention to remedy the situation.